Railway gondola car incorporating flexible panels of composite sheet material

ABSTRACT

A gondola railway car with a structural frame of metal has panels of lightweight composite tension-bearing sheet material attached to the frame by clamps which grip the margins of the panels. The panels thus are structural components of the car body, while also acting to contain bulk cargo such as coal. The panels may be of aramid fiber cloth coated with a wear-resistant polymeric material, and particles of hard material may be embedded in the polymeric material to enhance resistance to mechanical erosion.

This invention was made with government support under United States ofBureau of Mines Research Contract No. CO209005, Project #9008042-3. Thegovernment has certain rights in the invention.

BACKGROUND OF THE INVENTION

The present invention relates to railway cars and more particularly to arailway car of the open gondola type in which cargo is loaded andunloaded through the open top of the car.

Gondola railway cars are normally employed to carry bulk cargos ofgranular or lump-form materials such as coal, sand, and gravel.Conventional gondola cars are of metal construction and have acontinuous center sill structure extending the length of the car, and aflat bottom carried atop the center sill. Many of such cars are of astandard size in order to be unloaded by a dumper which turns the entirecar upside down.

Teoli U.S. Pat. No. 3,713,400 discloses a gondola railway car in whichthere is a parabolic shaped bottom between the trucks, but there is nofull-length center sill.

Jones et al. U.S. Pat. No. 4,361,097 discloses a gondola railway carhaving a continuous full-length center sill and a pair of longitudinallyarranged curvilinear troughs arranged one on each side of the centersill.

Landregan U.S. Pat. No. 4,331,083 discloses a gondola car in which alongitudinally central portion of the center sill is lower than theportions at the ends of the car.

Heap U.S. Pat. No. 4,408,542 discloses a gondola car with a full-lengthcenter sill and a longitudinal curvilinear trough extending the fullwidth of the car and extending beneath the center sill structure in alongitudinally central portion of the car.

While the gondola railway car structures previously known, such as thosedisclosed by the patents mentioned above, have certain advantages overthe previously known gondola cars, particularly regarding the height ofthe center of gravity, such cars are still heavier than is desired formost efficient use.

Particularly in gondola cars for use in carrying coal, aluminum has beenused to replace certain portions of structures previously made of steel,because of the ability of aluminum to withstand the corrosive effects ofimpurities, such as sulfur, commonly found in coal. Such aluminumstructure can also reduce the weight of such cars, allowing a greaterweight of cargo to be carried on each car, but aluminum construction isquite expensive, even considering the possibility of recovery of thealuminum from cars after their useful lifetime has ended. Therefore, itis still desired to provide a gondola railway car of adequate strength,but which is yet lighter than steel, less costly to construct andmaintain, and more durable than previously available railway cars forcarrying such types of cargo.

SUMMARY OF THE INVENTION

The present invention provides an answer to the previously stated needfor an improved railway car for carrying bulk cargoes of granular orlump-form products such as coal, that is of adequate strength, resistantto corrosion, light in weight, and yet is reasonable in cost forproduction and repair.

According to the present invention a railway car is provided in which astructural frame includes lower side sills and other rigid structuralmembers of metal, to which are attached tension-bearing panelsconstructed of strong tension-bearing material to define acargo-carrying container having a bottom portion including such panelsarranged to define at least one curvilinear trough portion.

In a preferred embodiment of the invention the tension-bearing panels ofthe railway car of the invention are of a flexible composite materialincluding a textile-based fabric coated with an elastic protectivematerial.

In one embodiment of the invention the tension-bearing panels include,on at least one side, a quantity of a wear-resistant particulatematerial embedded in the elastic protective material, in order toprotect the textile fabric layer of the flexible composite materialagainst wear.

In preferred embodiments of the invention the tension-bearing panels offlexible material are attached to the structural frame of the railwaycar by the use of clamp assemblies.

In one embodiment of the invention each tension-bearing panel has atubular margin of the flexible material containing a locking bar engagedby a clamp assembly attached to a portion of the structural frame of thecar body.

In one embodiment of the invention the cargo-carrying container portionof the car has upright side walls including panels of tension-bearing,flexible material whose margins are clamped to substantially rigidportions of the structural frame of the railway car.

In one embodiment of the invention upright arcuately curved transitionpanels help to define each end of the cargo-carrying container portionof the railway car.

It is therefore a principal object of the present invention to providean improved body structure for a railway car for carrying bulk cargos oflump-form materials such as coal.

It is another object of the invention to provide a strong,wear-resistant, flexible, and reasonably inexpensive material suitablefor use as tension-bearing panel portions of a cargo-carrying containerportion of a vehicle such as a railway gondola car for carryinglump-form bulk cargo.

It is another object of the invention to provide a clamp assembly forattaching tension-bearing panels to rigid frame structure members and toone another, in which tension in the flexible tension-bearing materialcauses the clamp assembly to grip the material more tightly.

The foregoing and other objectives, features, and advantages of theinvention will be more readily understood upon consideration of thefollowing detailed description of the invention, taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a railway car embodying the presentinvention.

FIG. 2 is a top plan view of the railway car shown in FIG. 1.

FIG. 3 is a bottom plan view of the body of the railway car shown inFIG. 1.

FIG. 4 is an isometric view showing one half of the car shown in FIG. 1.

FIG. 5 is a section view of the car shown in FIG. 1, taken along line5--5.

FIG. 6 is a view taken along line 6--6 of FIG. 2, at an enlarged scale,showing a clamp assembly holding a flexible panel attached to a portionof the structural frame of a railway car body according to theinvention.

FIG. 7 is a sectional view, taken along line 7--7 of FIG. 1, showing aclamping assembly for joining together adjacent panels of flexiblecomposite textile-based material in a railway car according to thepresent invention, while also attaching them to an element of astructural frame of the car body.

FIG. 8 is a view similar to that of FIG. 7, showing an alternativeclamping assembly for joining together adjacent panels of flexiblecomposite tension-bearing material.

FIG. 9 is a detail view showing the arrangement of a rigid end plate ina cargo trough portion of a railway car according to the invention.

FIG. 10 is a partially cut-away, face view of a part of a sheet of acomposite textile-based material suitable for use as a flexible panel ofa railway car according to the invention.

FIG. 11 is a sectional view of the composite textile-based materialshown in FIG. 10, taken along line 11--11, at an enlarged scale.

FIG. 12 is an isometric view similar to that of FIG. 4, showing a carhaving a bottom including a single bottom trough of suspendedtension-bearing material extending over the full width of the car.

FIG. 13 is a section view taken along line 13--13 of FIG. 12.

FIG. 14 is a top plan view of one-half of the body for a railway carshown in FIG. 12.

FIG. 15 is a bottom plan view of one-half of the body for a railway carshown in FIG. 12.

FIG. 16 is a side elevational view of a railway car according to thepresent invention, including a plurality of transversely orientedcurvilinear troughs defined by panels of flexible compositetextile-based material.

DETAILED DESCRIPTION OF THE INVENTION

Referring first to FIGS. 1-9 of the drawings which form a part of thedisclosure of the invention, a rail car 20 which is a preferredembodiment of the invention includes a body 22 having opposite ends 24and 26 each supported on a wheeled truck 28. A body bolster 30 islocated near each end 24, 26 of the body 22 and a center sill 32 extendslongitudinally of the car over its entire length.

A lower side sill 34, 36 is located on each side of the car 20,extending longitudinally parallel with the center sill over the distancebetween the body bolsters 30. Cross bearers 38 extend laterally abovethe center sill 32 between the lower side sills 34, 36.

Side wall upright members 40, preferably of "hat" section metal, areattached to the cross bearers 38 and the lower side sills 34, 36 and areinterconnected by side wall top chords 42 to define the location of anupstanding side wall 44 on each side of the car. An upright end post 46extends above the center sill 32 at each end 24, 26 of the car, and ahorizontal top chord end member 48 with an arcuate inner margin 50extends to each end post 46 from the nearest side wall upright member40, on each side of the car 20.

Horizontal transverse braces 52, which are preferably made of tubularaluminum, interconnect and provide mutual support between the upperportions of laterally opposite ones of the side wall upright members 40.Diagonal cross braces 54 of similar construction extend diagonallyupward from the centers of the cross bearers 38 to connecting platesattached to the side wall upright members 40, to provide a stiffstructural frame for the car. While the center sill 32 and body bolsters30 are assembled by welding together structural elements made of rolledsteel or bent steel plate, the lower side sills 34, 36, side wallupright members 40 and side wall top chords 42 are preferably ofaluminum to reduce weight and resist corrosive effects of coal.

The enclosure of a cargo-carrying container portion of the car isdefined primarily by side wall panels 56, connecting end transitionpanels 58, and bottom panels 60 of strong, wear-resistanttension-bearing, flexible, composite sheet material whose margins aresecurely clamped to respective elements of the structural frame of thecar. A horizontal floor end portion 62 and a sloping floor portion 64 ofthe bottom of the cargo-carrying container portion, adjacent and abovethe body bolster 30 at each end of the car, are preferably constructedof aluminum plate material, as are a pair of laterally opposite sidewallpanels 66 at each end of the car.

The side wall panels 56, of composite sheet material, the end transitionpanels 58, and the bottom panels 60 are all generally rectangular andare attached to the respective elements of the structural frame of thecar by elongate clamp assemblies 68 or 70, which will be describedpresently in greater detail. Because of this attachment the panels 56,58, 60 serve not only to contain cargo but also to carry tensile stressloads as part of the structure of the car body 22.

The bottom panels 60 are curved about a longitudinally-extending axis ofcurvature, forming curvilinear troughs 72 extending lower than thebottom of the center sill. The longitudinal margins of each panel areattached to the respective side wall 44 by clamp assemblies 70 mountedon a flange 74 extending upward from and along the inner side of the topof the lower side sill 34 or 36, and are connected by clamp assemblies68 to respective diagonally downwardly- and outwardly-directed bottomflanges 76 of the center sill 32.

An arcuate transverse support strip 78 extends downward beneath thesloping floor portion 64 adjacent the body bolster 30. As shown in FIG.9, the transverse support strip 78 is attached to an aluminum end plate80 attached, through a flexible curved margin portion 82, to the slopingfloor portion 64, to complete closure of the bottom of thecargo-carrying container portion of the car body 22.

Longitudinally adjacent ones of the bottom panels 60, in a car wheresuch bottom panels do not extend the full length of the car body 22, areconnected with each other to transfer tension longitudinally of the carby clamp assemblies 84, shown in FIG. 8, which carry tension-loadinglongitudinally of the car between adjacent ones of the bottom panels.

Referring to FIG. 6, the clamp assembly 68 is seen to include atension-carrying elongate projection in the form of a clamp-retainingrail 86 extending parallel with, but spaced a small distance apart from,the rounded margin 88 of the respective structural frame member, such asthe diagonally downwardly-extending flange 76 of the center sill 32. Theclamp-retaining rail 86 may be welded to the structural frame member orbe an integrally made part of it. The clamp-retaining rail 86 has aninclined contact face 90 to receive a hook portion 92 of a clamp bar 94.The clamp bar 94, which may preferably be of extruded aluminum, includesa heel portion 96 defining the hook 92 whose shape mates with theinclined face 90 of the clamp-retaining rail 86. The heel 96 also has amating surface 98 which rests snugly against a mating surface 100 of theflange 76. A central rib 102 of the clamp bar 94 extends toward theflange 76 and defines holes spaced apart from one another along thelength of the clamping bar 94 to receive fasteners such as bolts 104 tofasten the clamping bar 94 to the flange 76 in a position establishedcooperatively by the central rib 102 and the heel 96.

A locking bar 106 is located within a tubular margin portion 108 of aflexible bottom panel 60 fastened to the center sill 32 by the clampingassembly 68 shown in FIG. 6. The locking bar 106 preferably has a shapeproviding surfaces whose shapes correspond with those of the adjacentsurface of the respective structural frame member of the portion of thecar to which the panel is attached by the clamping assembly 68 at anyparticular location, and of the inner surface 110 of the outer or toeportion 112 of the clamp bar. A toe margin portion 114 of the clamp bar94 is spaced a small distance apart from the opposite surface of theflange 76 or other structural element of the structural frame of the car20, forming an elongate slot 115 through which the panel is free to moveto pull the locking bar 110 into a position within the cavity 118between the toe portion 112 of the clamp bar 94 and the structural framemember of the car body 22 providing a large area of surface contact oneach side of the locking bar 106, and thus compressing a correspondinglylarge portion of the tubular margin 108 of the bottom panel 60 or otherpanel, depending on the location of the particular clamp assembly 68,between the locking bar 94 and the adjacent surface of the flange 76,and between the arcuate surface of the locking bar 106 and the arcuateinner surface 110 of the toe portion of the clamp bar.

The surfaces of the locking bar 106, the flange of the structuralelement of the car, and the arcuate concave inner surface 110 of theclamp bar 94 are all generally smooth, rather than being knurled,grooved or toothed, in order to avoid cutting or puncturing and thusweakening the structure of the composite sheet material forming thetubular margin portion 108 of the panel. The angle 116 defined betweenthe surface of the flange and the outer surface of the locking bar,however, is designed to be wide enough to avoid having the locking barwedge between the toe portion 112 of the clamp bar 94 and the flange ofthe structural element of the car. As a desired result, when tension inthe tubular margin 108 is relaxed, as when the car is unloaded or whilethe structural frame of the car is flexing as the car is traveling alonga railway track in a loaded condition, it is possible for portions ofthe tubular margin 108 of the panels to move slightly and thus adjusttheir positions with respect to the respective clamp assemblies 68 toachieve more equal distribution of tension loads through the panels.

The clamp assemblies 70, shown in section view in FIG. 7, include aclamp bar 118 having a central rib 120 defining holes to receivefasteners such as bolts 104 to connect the clamp bar 118 to a structuralframe member of the car 20, such as the flange 74 atop the lower sidesill 34 or 36, or the central face 122 of the side wall upright members40. A respective toe portion 124 extends away from the central rib 120in each direction to define a respective elongate cavity 126 and slot128 to receive the tubular margin 108 and a respective locking bar 106for a panel 56, 58 or 60 of composite sheet material on each side of theclamp assembly 70.

The clamp assembly 84 shown in FIG. 8 may be used to connect paralleltubular margins 108 of panels of composite sheet material, such asbottom panels 69, where there is no adjacent structural frame element ofthe car body 22, as where the structural panel 60 of composite sheetmaterial cannot easily be made in a large enough size. The clampassembly 84 includes a pair of similar clamp bars 130 each resemblingthe clamp bar 118 of the clamp assembly 70 described above. The pair ofclamp bars 130 are held together by fasteners such as bolts 132 spacedapart along the rib 134, and thus define elongate cavities 136 and slots138 to receive the tubular margins 108 of adjacent composite panels,with locking bars 140 held within the tubular margins 108.

Each of the tension-bearing panels 56 of the side walls 44, the endtransition panels 58, and the bottom panels 60 is preferably of asimilar composite material 142, shown in FIGS. 10 and 11, which isprimarily a textile-based fabric layer 144, covered with a protectivecoating to protect the textile fibers which provide the bulk of thetensile strength of each panel from mechanical abrasion, from harmfulchemical reactions, and from potentially damaging radiation. A preferredmaterial for the flexible fabric layer 144 of the composite material fortension-bearing for the car as described above is a plain weave cloth,woven of yarns of twisted fibers of an aramid polymeric material. Thearamid polymeric material available as textile fibers from E. I. Dupontde Nemours and Company of Wilmington, Del. under the trademark Kevlar 29is preferred, since it has adequate tensile strength, for example about400,000 psi, and a stiffness modulus of about 9,000,000 psi, yet is onlyabout one-fifth as dense as steel, whose tensile strength is less thanthat of the Kevlar 29 aramid material. The Kevlar 29 material is thuscapable of carrying the same tensile stress, using composite panels ofsignificantly lighter weight than that of equivalent panels of steelconstruction, yet at a lower cost.

Such cloth of Kevlar 29 textile obtained from High-Pro Form Fabrics,Inc. of Newark, Del., is of plain weave of twisted Kevlar fibers, andhas a tensile strength of about 1800 pounds per lineal inch of thefabric, which is woven of yarns twisted of many continuous, round,cross-section filaments each having a denier of about 1.5 and a diameterof slightly less than 0.5 mil. The surface of the cloth is scuffed toprovide desired absorption and adhesion of the coating materials appliedto form the composite material for the tension-bearing panels.

In preparing the composite material for use as the panels according tothe present invention a coating 146 of a wear-resistant polymericplastic material such as a room temperature curing polyurethane materialis prepared and spread on each of the opposite surfaces of the aramidfiber cloth in a liquid form, and then is allowed to cure. The polymericmaterial adheres to the surface of the aramid cloth, extending a portionof the way into the yarns and among the fibers of the cloth, as shown at148 forming a partially impregnated layer of the aramid cloth covered bya layer of the polyurethane or other polymeric material on each side ofthe central layer 144 of aramid cloth. The central portion 150 of thecloth, however, may remain unimpregnated and thus free to flexibly carrytensile loads.

On at least one side of the composite textile-based sheet material thusformed, while the polymeric coating is still only partially cured, anouter layer 152 of the polymeric protective material is impregnated to asmall depth 154 with closely spaced particles of a hard wear-resistantmaterial such as alumina or silicon carbide, small enough to becomefully embedded and surrounded in a matrix of the polyurethane or otherpolymeric material of the coating layer 146. This provides additionalsurface hardness and resistance to mechanical erosion of the surface ofthe composite material of the flexible panels, particularly on the sideof each panel which will be in contact with cargo carried within thecar, yet the composite sheet material remains flexible enough to serveas the panels 56, 58 or 60 of the car body 22. The resulting compositesheet material 142 has a total thickness 156 of about 70-100 mils, ofwhich the coating layer 146 on each side, of polymeric material,extending somewhat into the aramid cloth 144, has a thickness 158 ofabout 20-40 mils. The particles of hard wear-resistant material areembedded to a depth 154 of preferably about 10-20 mils, so as to bespaced somewhat apart from the textile cloth of the composite sheet,which normally has a thickness 160 of about 30 mils.

An acceptable polyurethane material for use as the coating for thearamid cloth is a two-part polyurethane casting elastomer, availablefrom the Hexcel Corporation of Chatsworth, Cal. under the trade nameUralite 3177. When cured, the material has a tensile strength of about5,000 psi, permits elongation of about 6%, and has a Shore D hardness at75° F. of 72. Other materials, such as epoxy resins and polyamide resinswhich can also be applied by coating the Kevlar fabric are also useable.For example, a bisphenol A/epichlorhydrin based epoxy resin availablefrom the Shell Chemical Company as EPON® Resin 828, Product code 43240,would be usable. The previously-mentioned polyurethane coating materialis believed to be preferable, however, because of its greater ability toresist mechanical abrasion, its somewhat lower coefficient of friction,its capacity for elastic elongation greater than that of the aramidfiber, which preserves flexibility without delamination and cracking ofpanels of composite structure including such polyurethane coatings, andbecause it causes only negligible decrease in strength of the aramidcloth when used as a coating.

While such panels of composite structure are flexible, once the aramidfiber cloth layer 144 is coated with such a polymeric material it ismuch less flexible than when uncoated, and, as a result, the tubularmargin portions 108 of each panel 56, 58 and 60 are preferably leftuncoated by the polymer coating material until the Kevlar fabric hasbeen shaped appropriately to fit around the locking bar of theappropriate clamping assembly. The tubular margins may be formed bysewing the aramid cloth, and the polymeric coating material is also usedas an adhesive to help retain the margin in a tubular configuration.

Because of the directional characteristics of the aramid cloth it isdesirable to have the yarns oriented diagonally in the side wall panels56, while the yarns are preferably parallel with and normal to themargins of the bottom panels 60 and end transition panels 58.

In a car body 162 which is an alternative embodiment of the invention,shown in FIGS. 12-15, a single curvilinear trough is provided, thetrough being defined by a bottom panel 164 of tension-bearing compositematerial, spanning the entire width of the car body and having ahorizontal axis of curvature extending longitudinally of the car body.The opposite longitudinal margins of the bottom panels are connected,respectively, by clamp assemblies 68, to diagonally inwardly- anddownwardly-extending flanges 166 of parallel lower side sills 168, whichare preferably of steel, and the stub center sill 170 at each end of thecar body does not extend beyond the sloping floor portion 64. In such acar body 162 the horizontal floor 62 and sloping floor portion 64 arepreferably of steel and provide load bearing interconnection between thelower side sills 168, the stub center sill 170 and the body bolster 30at each end of the car body. The structure of the car body 162 above thelower side sills is similar to that of the car body 22, except thatthere may be greater use of steel in structural frame elements.

In a car body 172 which is a further alternative embodiment of theinvention, shown schematically in FIG. 16, bottom panels of compositeflexible sheet material of the type disclosed above are attached toconnecting strips 174 which extend arcuately beneath the lower sidesills on both sides of the car, to define curvilinear troughs 176extending transversely, that is, with horizontal axes of curvatureextending transversely of the car body, with transverse margin portionsof the bottom panels attached to transverse flanges extending diagonallydownward from cross bearers.

The terms and expressions which have been employed in the foregoingspecification are used therein as terms of description and not oflimitation, and there is no intention, in the use of such terms andexpressions, of excluding equivalents of the features shown anddescribed or portions thereof, it being recognized that the scope of theinvention is defined and limited only by the claims which follow.

What is claimed is:
 1. A body for a railway car for carrying granular orlump-type bulk cargo, comprising:(a) a pair of longitudinal lower sidesills; (b) an upstanding side wall extending above each said lower sidesill; and (c) a tension-bearing, cargo-supporting bottom panel of atextile-based sheet material having a longitudinally-extending marginattached to one of said lower side sills.
 2. The body for a railway carof claim 1 wherein said sheet material includes a main load-bearinglayer of a woven cloth of synthetic fiber.
 3. The body for a railway carof claim 1, including a clamp assembly associated with one of said lowerside sills and wherein said longitudinally-extending margin of saidbottom panel is attached to said one of said side sills by said clampassembly.
 4. A body for a railway car for carrying granular or lump-typebulk cargo, comprising:(a) a structural frame having a pair of oppositeends; (b) means including respective portions of said structural frame,for defining a cargo container, said cargo container including:(i) apair of opposite upstanding longitudinally-extending side walls; (ii) apair of opposite upstanding transversely-extending end walls; and (iii)a tension-bearing bottom panel of a textile-based sheet materialdefining a bottom of said cargo container, said bottom panel including alongitudinal margin portion interconnected with one of said side walls.5. The body for a railway car of claim 4 wherein said textile-basedsheet material includes a textile fabric covered by a protective coatingof material which is capable of greater elastic elongation than saidtextile fabric.
 6. The body for a railway car of claim 4 wherein saidtextile-based sheet material includes a textile fabric covered by aprotective coating of a polymeric plastic material and wherein aquantity of a particulate ceramic material is embedded in said polymericplastic material, with said particulate ceramic material supportedspaced apart from said textile fabric by a portion of said coating ofpolymeric plastic material.
 7. The body for a railway car of claim 4wherein said bottom panel extends from one to the other of said sidewalls and defines a longitudinal curvilinear trough having an axis ofcurvature extending longitudinally of said car.
 8. The body for arailway car of claim 4, each said end wall including an upstandingstructural frame member, said body further including a connecting panelof said flexible textile-based material extending as an arcuate,tension-bearing transition portion of said cargo-carrying containerbetween one of said side walls and an adjacent one of said end walls ofsaid car body.
 9. The railway car of claim 8 wherein said arcuateconnecting panel has respective margin portions attached to said sidewall and to said upstanding structural frame member of said adjacent endwall by respective clamp assemblies.
 10. The body for a railway car ofclaim 4 wherein a major portion of each said side wall consistsprimarily of at least one tension-bearing panel of textile-based sheetmaterial attached to a plurality of respective side wall frame membersof said structural frame.
 11. A body for a railway car for carryinggranular or lump-type bulk cargo, comprising:(a) a pair of longitudinallower side sills; (b) an upstanding side wall extending above each saidlower side sill; and (c) a plurality of tension-bearing cargo-supportingbottom panels, of a textile-based sheet material, each of said bottompanels defining one of a plurality of curvilinear troughs, each saidtrough having an axis of curvature extending transversely of said bodyand having an arcuately curved longitudinal margin thereof supported byone of said lower side sills.
 12. A body for a railway car for carryinggranular or lump-type bulk cargo, comprising:(a) a pair of longitudinallower side sills; (b) an upstanding side wall extending above each saidlower side sill; (c) a clamp assembly associated with one of said lowerside sills; and (d) a tension-bearing, cargo-supporting bottom panel ofa textile-based sheet material having a longitudinally-extending marginattached to said one of said lower side sills by said clamp assembly,said bottom panel including a tubular margin and a locking bar locatedwithin said tubular margin, and said clamp assembly including a clampbar adjustably attached to and extending along said one of said lowerside sills, said clamp bar and a portion of said one of said lower sidesills cooperatively defining an elongate slot and an elongate cavity,said locking bar and said tubular margin being located within saidelongate cavity and said clamp bar retaining said locking bar and saidtubular margin of said bottom panel between said clamp bar and said oneof said lower side sills, with said bottom panel extending through saidslot.
 13. A body for a railway car for carrying granular or lump-typebulk cargo, comprising:(a) a structural frame having a pair of oppositeends and a center sill interconnecting said opposite ends; (b) meansincluding respective portions of said structural frame, for defining acargo container, said cargo container including:(i) a pair of oppositeupstanding longitudinally-extending side walls including a pair of lowerside sills spaced laterally apart from said center sill and locatedrespectively on opposite sides of said center sill; (ii) a pair ofopposite upstanding transversely-extending end walls; and (iii) a bottompanel of a textile-based sheet material, said bottom panel including alongitudinal margin portion interconnected with one of said side walls,said longitudinal margin portion of said bottom panel being attached toa respective one of said side sills, and said bottom panel includinganother margin portion attached to said center sill.
 14. The body for arailway car of claim 13, including a pair of said bottom panels whereineach said bottom panel defines a respective one of a pair oflongitudinal curvilinear troughs each located between said center silland a respective one of said lower side sills and wherein each saidcurvilinear trough has a longitudinal axis extending longitudinally ofsaid car body.
 15. A body for a railway car for carrying granular orlump-type bulk cargo, comprising:(a) a structural frame including aplurality of structural frame members and having a pair of oppositeends; (b) means including respective portions of said structural frame,for defining a cargo container, said cargo container including:(i) apair of opposite upstanding longitudinally-extending side walls; (ii) apair of opposite upstanding transversely-extending end walls; and (iii)a plurality of tension-bearing panels of a textile-based sheet material,including a bottom panel having a longitudinal margin portioninterconnected with one of said side walls, said body including a panelclamp assembly attaching one of said plurality of tension-bearing panelsto a respective one of said structural frame members, said one of saidtension-bearing panels including a tubular margin, and a locking barbeing located within said tubular margin, said panel clamp assemblyhaving a clamp-retaining rail fixedly attached to said one of saidstructural frame members and including a clamp bar having a hooked heelside and a toe end margin, said hooked heel side matingly engaging saidclamp-retaining rail and said toe end margin cooperating with said oneof said structural frame members to define an elongate slot and anelongate cavity, said locking bar and said tubular margin of saidtension-bearing panel being held within said elongate cavity and saidpanel extending through said slot.
 16. The body for a railway car ofclaim 15 wherein said locking bar is of tapered oval cross-sectionalshape and said toe end margin portion of said clamp bar has acorrespondingly shaped inner surface for clamping said tubular margin ofsaid tension-bearing panel between said locking bar and said structuralframe member and between said clamping bar and said locking bar.
 17. Arailway car body for carrying bulk materials, comprising:(a) a pair ofside walls; and (b) a suspended tension-bearing floor of flexibletextile-based material, each of said side walls having a bottom marginand said floor having a pair of opposite parallel side margins, each oneof said side margins being attached to the bottom margin of a respectiveone of said side walls, suspending said floor between said side walls.18. A railway car for carrying bulk cargo, comprising:(a) an elongatecar body having opposite ends each supported on a respective wheeledtruck; (b) a pair of opposing upstanding side walls extendinglongitudinally of said car body; (c) a pair of opposing upstanding endwalls extending transversely of said car body; and (d) a tension-bearingconnecting panel of flexible textile-based material having respectivemargin portions attached respectively to one of said upstanding sidewalls and to an adjacent one of said end walls.